All of what has been said may be the culprit. I would buy several different loadings and see which gives you the best groups. If your still not satisfied, then ask someone else whose skills are better than yours to shoot it and get their opinion. If you decide to go to a smith, a trigger job and bedding will probably do you right. I had almost the same problem when I bought my 700 ADL in 257 Roberts. Remington and Federal loads wouldn' t give me anything under 3" at 100 yds. I tried Hornady Customs and my group size shrank to an inch after only three sighter shots and an adjustment on zero.